
theorem Th3:
  for L being non empty addLoopStr, F being FinSequence of (the
  carrier of L)* holds Sum (<*>((the carrier of L)*)) = <*>(the carrier of L)
proof
  let L be non empty addLoopStr, F be FinSequence of (the carrier of L)*;
  dom Sum (<*>((the carrier of L)*)) = dom (<*>((the carrier of L)* )) by Th2;
  hence thesis;
end;
